1. Field of the Invention
This invention relates to the chemical arts. In particular, this invention relates to lubricant compositions used for high temperature applications.
2. Discussion of the Related Art
Lubricating compositions are used to reduce friction between surfaces, which are moving with respect to each other. Lubricant compositions prevent contact between the moving surfaces, thus preventing harmful wear.
Lubricants in commercial use today are prepared from a variety of natural and synthetic base stocks admixed with various additives, depending upon their intended application. The base stocks typically include mineral oils, highly refined mineral oils, poly alpha olefins (PAO), polyalkylene glycols (PAG), and phosphate esters, as well as silicone esters, diesters and polyol esters.
Thermal and oxidative stability requirements and the accompanying need for lubricant compositions with greater stability have been increasing. In end uses where higher stability is desired or required, polyol esters have been commonly used due to their high thermal and oxidative stability. Among the most demanding lubricant applications in terms of thermal and oxidative requirements are lubricants used in high temperature ovens and aluminum extrusion operations, where operating temperatures and exposure to oxygen are both high.
Accordingly, there remains a need for a lubricating composition possessing desirable thermal and oxidative stability under high temperature conditions, such as the conditions attendant to high temperature ovens and aluminum extrusion operations. The present invention satisfies these and provides further related advantages.